Application characteristics of vane rotary cylinder, working principle of vane rotary cylinder structure

Blade type rotary cylinder application


Blade-type rotating cylinders are usually suitable for mining machines, pneumatic tools, lifting devices, mixers, special equipment, etc.


In order to adapt the rotating cylinder to different applications, it is often equipped with some auxiliary devices: such as a transmission mechanism, which is used to reduce its rotational speed to an appropriate value. The most commonly used is a planetary transmission mechanism. The adjustment mechanism is used to limit the no-load speed of the rotating cylinder. The effect is the same rated speed, but the no-load speed is lower. When the load changes, the speed change is small.



Features of vane rotary cylinder


① Bidirectional rotation can be achieved;


② Small size, high output power per unit;


③Since leakage is difficult to avoid, its efficiency is limited;


④ Reliable operation, low maintenance and protection costs;


⑤ It must be effectively lubricated no matter what;


⑥Power range is 0.05~20kW;


⑦The speed range is 200~80000/min;


③The characteristics of the vane type rotary cylinder are not good at startup and low-speed operation. When used in situations where the rotation speed is below 500r/min, a reduction mechanism must be used.





Vane type rotating cylinder structure


The vane rotary cylinder is mainly composed of a stator, a rotor, a blade and a casing. There are gas distribution slots for intake and exhaust on the stator, long slots are milled on the rotor, and blades are installed in the slots. Both ends of the stator are covered with sealing covers, and the rotor and stator are installed eccentrically. In this way, the blades sliding in the radial direction and the inner cavity of the housing form a working chamber of the rotating cylinder. The number of blades directly affects the efficiency, starting performance and smoothness of movement of the rotating cylinder. It is usually 3 to 5 blades, and can reach 10 in special circumstances.


There are front and rear cover plates on both sides of the rotor. The blades can slide radially in the slots of the rotor. Compressed air is passed through the bottom of the blades. The rotor rotates by centrifugal force and the air pressure at the bottom of the blades to press the blades against the inner surface of the stator. There are semicircular grooves in the stator to provide compressed air and discharge exhaust gas.





Working principle of vane rotary cylinder





The working principle of the rotary cylinder is similar to that of the hydraulic rotary cylinder. The compressed air enters from the input port A and is divided into two paths. One path enters the bottom of the blade through the grooves on the sealing covers at both ends of the stator (not shown in the picture), and pushes the blade out against the stator;the other path enters through the blade. The crescent-shaped closed space composed of the stator, the rotor and the sealing covers at both ends acts on the blades on both sides of the working chamber to generate a force that causes the rotor to rotate. Due to the eccentric installation of the rotor, multiple sickle-shaped working cavities are formed. The two blades have different extension lengths, which causes the air pressure to act on different areas and generates a torque difference, causing the rotor to rotate in the counterclockwise direction. When the central rotor rotates, , the volume of the working chamber changes, creating a pressure difference on the blades of the adjacent working chamber, and the pressure difference is used to push the rotor to rotate. The seal between the blade and the inner surface of the casing is ensured by its own centrifugal force during the working process, and is achieved by introducing compressed air at the bottom or using a spring during the startup phase. The gas after work is discharged from the output port. If the input direction of the compressed air is changed, the rotation of the rotor can be changed.

As shown in the figure, the vane type rotary cylinder adopts a structure that does not expand the compressed air, that is, non-expansion type. The working principle is as described above. As shown in the figure, the vane rotary cylinder adopts a structure that maintains the expansion stroke of compressed air. When the rotor rotates to exhaust port C position, the compressed air in the working room is exhausted once, and then the remaining compressed air continues to expand until the rotor rotates to output port B position for secondary exhaust. This structure of the rotating cylinder can effectively utilize the energy generated when part of the compressed air expands and increase the output power. Compared with the expansion rotary cylinder, the non-expansion rotary cylinder consumes large amounts of air and has low efficiency;it has large output power per unit volume, small size and light weight.